PHP Warning: Unknown: POST Content-Length of 28 bytes exceeds the limit of -2147483648 bytes in Unknown on line 0

If you are noticing the above error in apache error logs and having problems for login scripts the problem is with post_max_size variable in php.ini

Here is what you need to do, Find out the correct php.ini configuration file.

root@server [/usr]# php -i | grep php.ini

Configuration File (php.ini) Path => /usr/local/lib
Loaded Configuration File => /usr/local/lib/php.ini

Edit the loaded php.ini file and check for post_max_size variable value, Set it to 8M which is best recommended.

root@server [/usr]# grep post_max /usr/local/lib/php.ini

post_max_size = 8M

Then restart apache, That should resolve the problem.